from re import S


class NestedInteger:
    nums = []
    index = 0
    def __init__(self, nestedList=None):
        """
        If value is an integer, store as an integer
        If value is a list, store as a list of NestedInteger
        """
        if isinstance(nestedList, int):
            self.nums.append(nestedList)
        elif isinstance(nestedList, list):
            for i in nestedList:
                self.nums.append(i)
            

    def isInteger(self):
        """
        @return True if this NestedInteger holds a single integer, rather than a nested list.
        :rtype bool
        """
        return isinstance(self.nums[self.index], int)
    
    def add(self, ele):
        """
        Set this NestedInteger to hold a nested list and adds a nested integer ele to it.
        :rtype void
        """
        self.nums.append(ele)


# """
# This is the interface that allows for creating nested lists.
# You should not implement it, or speculate about its implementation
# """
#class NestedInteger:
#    def __init__(self, value=None):
#        """
#        If value is not specified, initializes an empty list.
#        Otherwise initializes a single integer equal to value.
#        """
#
#    def isInteger(self):
#        """
#        @return True if this NestedInteger holds a single integer, rather than a nested list.
#        :rtype bool
#        """
#
#    def add(self, elem):
#        """
#        Set this NestedInteger to hold a nested list and adds a nested integer elem to it.
#        :rtype void
#        """
#
#    def setInteger(self, value):
#        """
#        Set this NestedInteger to hold a single integer equal to value.
#        :rtype void
#        """
#
#    def getInteger(self):
#        """
#        @return the single integer that this NestedInteger holds, if it holds a single integer
#        Return None if this NestedInteger holds a nested list
#        :rtype int
#        """
#
#    def getList(self):
#        """
#        @return the nested list that this NestedInteger holds, if it holds a nested list
#        Return None if this NestedInteger holds a single integer
#        :rtype List[NestedInteger]
#        """
class Solution:
    def deserialize(self, s: str) -> NestedInteger:
        if s[0] != '[':
            return NestedInteger(int(s))

        stack, num, negative = [], '', False

        for i, c in enumerate(s):
            if c == '[':
                stack.append(NestedInteger())
            elif c == '-':
                negative = True
            elif c.isdigit():
                num += c
            elif c == ',' or c == ']':
                if num != '':
                    num = -int(num) if negative else int(num)
                    stack[-1].add(NestedInteger(num))
                num, negative = '', False
                if c == ']' and len(stack) > 1:
                    ni = stack.pop()
                    stack[-1].add(ni)
        return stack.pop()
